Monocotyledons with Petaloid Flowers . 
“3 
Natural Order 
AROIDEJE. Tab. 89. 
Diagnosis.— Herbs or, in tropical species, often shrubby climbers, with 
frequently net-veined leaves. Flowers small, sessile, upon a simple spadix, 
naked or with a scaly perianth, unisexual or bisexual. Ovary free, with one 
or more cells. 
Distribution. —A large Natural Order, chiefly confined to humid Tropical and Subtropical 
countries. A few herbaceous genera with radical leaves are represented in Europe, one genus extending 
northward into Scandinavia. The only two British species belong to distinct genera, representing each 
of the two Sub-orders into which Aroidese are sometimes divided, viz.:— 
I. ARACE/E.— Flowers usually unisexual, destitute of a perianth. 
II, ORONTIE^E.—Flowers usually perfect, with or without a scaly perianth. 
Number of British Genera, 2 ; Species, 3. 
Leaves petiolate, hastate and net-veined in Cuckoo-pint {Arum maculatum); narrow, sword-like and parallel- 
veined in Sweet Flag ( Acorus). 
SPATHE ample, convolute, sheathing the spadix in Cuckoo-pint : phyllodineous, forming an apparent direct 
continuation of the peduncle from the base of the spadix in Sweet Flag. 
SPADIX in Arum bearing a ring of naked, closely-packed pistillate flowers and a few imperfect carpels at the 
base, at a short interval above a ring of sessile anthers and a few staminodes, and terminating in a club-shaped sterile 
appendix: in Sweet Flag densely covered throughout with numerous hermaphrodite flowers, each with a 2-3-celled 
ovary, 6 stamens and 6 perianthial scales. 
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